Hi Peter,
it should read IO360A3B6D. Anyway, better look for a A3B6, the "D" model having the troublesome double magneto. Specific parts for those may become harsh to find and two separate mags is just better and safer.
Andi

Andi, thank you for the comment. I have double checked - it is IO-360 A1B6D. I can try to get a engine "without D". My general question: I s it possible to use other models of the IO-360 A series such as A2B, A3B...?
Peter

Hi,
only the very first "J"'s had the A1B6D variant. The current variant is A3B6. Lycoming remans come without "D". The reason: Bendix (the manufacturer of the Double Magneto) has merged into Continental and Slick into Lycoming's parent company.
See all O-360 versions here: en.wikipedia.org/wiki/List_of_Lycoming_O-360_variants